Developing tank for developing photographic films



Oct. 11 1949. s. FREEMAN 2,484,378

DEVELOPING TANK FOR DEVELOPING PHOTOGRAPHIC FILMS 3 Sheets-Sheet 1 Filed Jan. 19, 1945 INVENTOR. v/w a/vv BY mac/w HM ATTORNEYS- Oct. 11, 1949. s. FREEMAN DEVELOPING TANK FOR DEVELOPING PHOTOGRAPHIC FILMS .3 Sheets-Sheet 2 [VI]! il n! IULM D 4 Filed Jan. 19, 1945 INVENTOR. 47 4 f /Lwmaw ATTORNEYS.

S- FREEMAN Oct. 11, 1949.

DEVELOPING TANK FOR DEVELOPING PHOTOGRAPBIC FILMS Filed Jan. 19, 1945 3 Shoots-Sheet 3 INVHVTOR.

W 5mm malfr MM ATTORNEYS.

Patented Oct. 11, 1949 UNITED STATES OFFICE DEVELOPING. TANK FDR.DEVELOP.INGr,v PHOTOGRAPHIC- FILMS Samuel Freeman, New: York, NZ. Y.

Application. January 19, 1945,, SerialLN'o. 573,599

My invention relates to a new and improved developing tank for developing photographic films.

One of the objects-of my invention is to improve the tank which is disclosed in U. S. Patent No. 2,214,581 which was issued to me on September' 10, 1940.

In addtion to havingthe advantages described in said U. S. Patent No. 2,214,581, the improved device automatically separates the'protecti've paper from the film by merely turning the holding spool on which the film and'protective paper are spirally wound, thus making it unnecessary to pull the end of the protective paper which. proj ects out of the tank.

In addition, the improved device permits the ready separation from the film, of the end -portion of the protective paper'which is adherently connected to" the film; This eliminates the possibility of tearing or rupturing the strip of pro tective'paper, if its? endportion adheres tightly to the film. Such. tight adherence can occur especially in coldweather.

Other objects of my invention are to provide a device which is more simple and reliable to construct and to operate.

Numerous additional important objects and ad vantages-of my invention will be stated? in the annexed descriptionand drawings which illustrate preferred embodiments; thereof.

Fig. 1 is. atop plan View of the improved de.-- vice. withthe cover removed.

Fig. 2. is a vertical elevation, partially in section, of the. improved device,- showing the cover in. its operative position.

Fig. 3 isatop plan view of thecover, detachedfromthe casing.

Fig. 4- is a sectional view on the line. 4-4 of Fig. 3..

Fig. 5 is a bottom plan view of the hood which is provided for the holder of the knife.

Fig. 6 is a detall sectional Viewwhich-illustrates theloadingof theholder-with the film.

Fig. '7- is a detail. elevation which shows the means for clamping the roll of film and paper within the holder.

Fig. 8 is a sectional view on the line. 8-&- of Fig. '7. This shows, in broken lines, the position of the film-spool, when it has beeniully unloaded.

Fig. 9 is a bottom plan view of a. modification 2-. protective paper is led from the holding spool to the outlet channel in a curved path, whereas, in the embodiment of Fig. 2, the protective paper is led to the outlet channel from the holding spool. over the respective edge of the slit of the holder, in an upward vertical path.

Fig. 12 is a sectional view which illustrates a modification, in which each wall of the outlet channel for the protective paper, is provided with a liner which is made of either soft or flexible filamentous material, in order to provide a seal against the admission of" light.

1'3 shows a modification of the holder, for guiding films of" different respective widths, into the guides which guide the film into the take-up spools.

The device comprises a tank I which can be made of any suitable material which is inert to the developing solution. A shaft 2 is j'ournaled in suitable bearings which are provided in the front and rear'wall's of said tank I". As in said previously issued patent; respective take-up spools 3 are adjustab-ly' fixed to the shaft 2'. These take-up spools 3 can be moved along the shaft 2, forta king up films of difierent widths. When the adjustment of spools 3. has been made, said spools 3 are then clamped or otherwise secured to shaft 2. The walls of said spools 3, which face eachother', are provided respectively with spiral grooves G, as insai d'previously issued patent. Each respective spiral groove G of each spool 3,- has an inlet end which is close to the center of the respective spool 3.

As shown in Fig. 1i and Fig. 2, a gear 4 is fixed to therespective-adjacent spool: 3., The gearl may be made integral with; the respective spool 3. The shatt 2. and the-two spools 3 and the gear 4 turn in unison.

A. rod 5 is turnably, mounted-in respective recesses of the front and rearwalls of the tank l. Saidrecesses are. open at their tops, so that the rod 5 can be lifted-out of said recesses. Respective film-guides 6 are'fixed detach-ably ad Ia. These internal walls la are inclined-.=trans.--

versely. towards each other,. in order transversely to arch. the. film. between the narrowest portion of the film-guide which. is provided by saidv internal guide-walls la.

The grooves G in the proximate faces of the spools 3 are of sufficient depth, so that the film is not transversely arched when it is located in said grooves G. Since the film is resilient, its temporary transverse arching between the internal guide-walls 1a, causes the film to spread transversely into the grooves G without transversely arching said film, thus reliably seating the edges of the film in non-arched shape in the grooves G. Each said guide 6 is provided with a hollow hub 8 in which the rod 5 is seated. As shown in Fig. 10, the rod 5 is provided with a rib which is seated in a corresponding recess of the respective hub 8, so that the rod 5 and the hubs 8 turn in unison. Each hub 8 is transversely adjustable along the rod 5. This enables the device to receive films of different Widths. After the guides 6 have been thus transversely adjusted, their respective hubs 8 are held in adjusted position, by means of detachable tapered pins 9, which have tight fits in correspondingly aligned bores of the hub 8 and the rod 5.

As in U. S. Patent No. 2,214,581, a flexible pull member has its lower end fixed to the shaft 2, so that the flexible pull member ID is wound spirally around the shaft 2, when said shaft is turned in the proper direction. A clamp II is fixed to the outer end of the flexible pull member ID. This clamp II can be detachably fixed to the end of the roll of film which is to be developed. Ordinarily, said end of the roll of film has a paper strip to which said clamp i can be fixed.

As shown in Fig. 2, the tank I is provided with an external compartment I2. The loader I4 is turnably mounted in said compartment |2. This loader i4 is of general cylindrical shape. Said loader has a longitudinal slit whose edges are defined by the edge-walls and I6. One end of said loader I is open, so that the roll of film can be inserted longitudinally into said loader l4. One end of said loader i4 is closed, and said closed end is provided with an operating knob 11, which is located externally and in front of the front wall of the compartment l2, when the loader 4 is located in operative position. The end wall is of said compartment i2 is closed. The closed end of the loader I4 is provided with a flange 9, which fits snugly and light-tight in the open front wall of the compartment l2, when the loader I4 is in position.

Adjacent the knob H, the hub of a latch 20 is turnably mounted upon a stud of the loader !4. The knob i! prevents the hub of latch 23 from slippinrr off holder I4. As shown in Fig. 3, the cover 2| is provided with a half-cylindrical flange 22. The latch 20 is provided with an inwardly bent hook-end 23. which can be moved over the half-cylindrical flange 22, so that the latch 20 then detachably locks the cover 2| in light-tight position on the tank I.

A clamping frame 25 is located in the loader M. Said clamping frame 25 comprises a base 24 which is of general trough or half-cylindrical shape.

The spirally wound mass of film and protective paper. which is located on its holding-spool 39. always frictionally abuts the base 24. When the holding-spool 3|! is empty, said holding-spool abuts said base 24. The disc flanges 3| of the holding-spool never contact with the base 24, save possibly at the inner end-faces of said flanges 3!.

Res ective disks 26 are fixed to the base-sections 24a and 24b of base 24. Each disk 25 is provided with a through-and-through slot '21. In

this illustrative embodiment, each said slot 2'! is eccentric relative to the respective center of the respective disk 26. This is an optional feature, because the longitudinal walls of said slot 21 can be disposed symmetrically, relative to a respective diameter of the disk 26.

The respective slots 21 of the respective disks 25 are parallel to and alined with each other.

A shaft 28 is turnably mounted in suitable bearings which are provided in the disks 25. A torsion spring 29 is coiled around said shaft 28. One end of the torsion spring 29 is fixed to the shaft 28. The other end 29a of the spring 28 abuts the base-section 24a.

The spiral roll of film and paper is wound upon the usual cylindrical holding-spool 30, which has the usual enlarged disc-shaped flanges 3|. Said holding spool 30 has a bore, in which a rod 32 is located. This rod 32 extends through the respective slots 21. Respective clamping rods 33 are fixed to the shaft 28.

When the rod 32 is in operative position, the torsion spring 29 biases the clamping rods 33 to press against the respective exposed end-portions of the rod 32, so that said rod 32 is forced towards the sections of the base 24, thus firmly pressing the outermost layer of the spirally wound roll of film and paper which is wound upon the spool 33, against the base sections 24a and 24b.

As shown in Fig. 7, each disk 26 is connected to its respective base-section 24a or 24b, by a, U- shaped member, thus providing a space into which the respective flanges 3| can extend.

The pressure of the clamping rods 33 is maintained by spring 29, so that a part of the periph-' 'ery of the spirally wound roll of film and paper F, P on the spool 30, is always pressed against the base-sections 24a and 24b. This provides frictional retarding means for retarding the unwinding of the material from the spool 30, thus insuring even and uniform unwinding. As the film F and paper P are unwound from the holding spool 30, its flanges 3| continue further to enter the spaces between the disks 26 and the base-sections 24a and 24b, until said flanges 3| are finally in the positions shown in broken. lines in Fig. 8. The empty holding spool 33 now contacts with, and it is pressed against, the basesections 24a and 24?), between the flanges 3|.

The entire frame 25, together with the spool on which the combined roll of film and paper is Wound, can be slid longitudinally into the loader |4, through the open end-face of said holder. The discs 26 can fit tightly enough in the loader I4, so

that the frame 25 and the loader [4 turn in unifore, when the rod 32 is detached from the frame 25, in order to locate the spool 30 in the base 24, the movement of the arms 33 is limited by said stop 34, thus preventing the unwinding of the torsion spring 29. In order to provide adjustment for films of different widths, the base 24 is preferably, but not necessarily, made of said two separate sections 24a and 2472. Each of these sections is provided at each of its edges with an eye 35. The eyes 35 of base-section 2411 are slidable on respective rods 36. At the bottom of each section 24a and 24b, an additional eye 31 is provided. The section 2417, which is fixed to the respective disk 26, has its edge-eyes 35 and its botsnag-arotom eye. 31, fixedto-the respective threerods 36.-

The three corresponding loops-of: section. 24a, are:

slidable onthe respective rods 36.

The two toprods-36 are detachably fixed to one of the disks; 26. Said respectivedisk 26 is at the,

right of Fig. 7. For this purpose, each said top rod 36 is provided with. an external. thread 38.

Lock nuts 39 are provided for detachably fixing; each-top rod; 36130 the respective disk 26. The

after it has been loaded with the spool 30 and the combined film and protective paper F, P which. is wound on said spool 30. In said position, edgewall It of the slit of loader I4, is substantially vertically ali-ned withth'e-axis of said: loader l4;

While the loader Mis located in its initial loadingiposition' as shown inFig. 2, the film F and the protective paper P'are unwound from spool 30, by pulling upon the outer free. endof the'protective paperP, until the pull-strip isexposed.

The length or the unwound protective'paper P is. sufficient at this point, sothat the unwoundend-portion of said paperrPcan be led: over the flange: M compartment [2; so that the" free edge of said protective paper P is located below the bottom of flange H.

The loader i4 is now turned counterclockwise from the position shown'in-Fig. 2; The top'wall of. shoulder 44' of theloader I4, thus. clamps the protective paper P and the pull-strip, againstthe respectiveinternal wall'of compartment [2; The

clamp H is now fastened to the end of'the'pull' strip.

Theloader M can be-detachably locked in the position in which paper 1? and the pull-strip are" thus clamped-,by means of a pin-:54; which is downwardly biased by a spring 55. The tipv of pin 54. enters a transverse groove of loader Hi. This groove hasoutwardly inclined walls, s'o-that said groove can be released from the pin 54, by

exerting. sufficient turningforce upon: the'holder in the colchwi'se direction, by meansof'kriob Hi Thisv prevents the loader l4 fromturning acci-- dentally out of its said clamping, position, while the clamp 1.! is. fastened to the pull-strip.

The cover 2! is applied-andlatched, while the loader I4 is in said clamping position.

The loader I4 is then turned clockwise back to the positionshown in'Fig. 2, which is now an unwinding position, until its shoulder 44 abuts-acorresponding internal. flange of the inner wall. of compartment l2.

The protective paper P is now located in and below the outer bottom end of channel 4-3, which is between the wall Ml of flange 4|, and a corre-- sponding flange 12' of cover 2|. The. protective paper P either forms a light-tight filling in said channel E3, or if not, the curved shape. of saidchannel' 43 and of the paper P therein preventsthe entry of light.

After the cover has been thus located andv locked, and the pull-strip has been fixed to clamp II, the shaft 2 is rotated by rotatinga knob 45, which is detachably fixed to a shaft 1 6 which is journaled in suitable bearings which are. provided'in'the cover 2!. A gear 41 is fixed to said shaft 46. When the cover H is l'ocatedin operative position; gear 41 meshes Withgear 4. Therefore, bytuming: the knob 45 counterclockwise, the gearl and the shaft 2 will be turned clockwise, thus pulling the. film F off the spool'38, and winding thefil-mF spirally in the grooves G of the spools 3.

The gears 4 and 41 make it unnecessary to extend. the shaft; 2. through the wall of. the tank, thus eliminating leakageof the: developing. solution. The shaft. 2 is located wholly within the tank. Byusing said gears, it is possible to fill the tank with developingsolution, to the top of gear 4. Hence all the filmwhich is located in the grooves G of the take-up spools, is immersed in the developing, solution. When the film is thus taken. up in said groooves G, wholly separated from; the protective paper P, a few turns of said take-up spools 3iwill eliminate air-bubbles which cling to the film. If the take-up shaft 2 extends through a. wallnof the tank, it is practically impossible to provide the shaft 2- with a leak-proof bearing. Hence, if the gears 4' and 41 are omitted,

without the substitution of an equivalent, the

tank. can be filled. with developing solution, only tothe-take-up shaft 2. In such'case; thev upper half of the film in'grooves G is above the: developi-ng solution. the shaft 2 at frequent intervals-during: the developing periodto eliminate air bubbles, as such air bubbles spot the film. Likewise, if only-part of. thefilm is immersed in the-developing solution; the takeup shaft 2 must be turned at. frequent intervals, in order to secure'proper uniform development.

While'the film is'thusbeing unwound; the protective paper P is simultaneously unwound and fed outwardly through thechannel 431.. The pro-- tective paper P has natural resilience, an it is unwouncllin a directionopposite: to the curler set which isimparted to said resilient paper P, by the winding of said. papen together with the-film, upon the spool3.0.

Therefore, said protective paper P has'sufficient stiffness so that it can be ieds automatically throughthe-spaceu by turningspool: Silhy meansof pull-member H1, without pulling; the paper P manually...v For this purpose, the walls of the channel 43 are curved in order topermitan easy and reliablemovement of thepaper P through the. channel 43..

While the spool 351 is being turned so to unwind the film and protective Paper therefrom, the loader i4 is. held in the position shown in Fig. 2, becausev the unwinding pull on the film urges the loader I4 to turn clockwise; The protective paper P is led over the edge wall l5. of the slit during. the unwinding, upwardly in asubstantially vertical direction, and through thechannel 43. There is-little or. no bend. of the protectiv paper P over the edge Wall [-5, thus mini-mizi-ngfriction, so that the stiffness of the paper P is-sufficient to push the paper P through thechannelAfig without pullingthe exposed portion of the paper.

It is then necessary to turn 7 configuration of the walls of the channel 43, as long as said configuration permits the automatic feeding of the paper through said space 43.

After the film has been wholly Wound into the grooves G, it is necessary to cut off the inner end of the strip of paper P, or to sever the fastening strip. As an alternative, the inner endportion of the film F can be severed.

For this purpose, I use a knife 48 which is transversely slidable in a slot 51 of cover 2|. Said knife 43 is fixed t slide-rod 49 which is laterally slidable in a tube 50 which is fixed to a hood or enlargement i of the cover 2|. A knob 52 is fixed to one end of the slide-rod 49. The tube 50 has an externally threaded end which projects in front of the cover 2|. The internal wall of said knob 52 is tapped so that said knob 52 can be detachably locked to the respective end of the tub 50. The knob 52 is turnable on the sliderod 49, and it is held against slipping off the sliderod 49.

The knife 43 clears the film, when knob 52 is detachably locked to tube 50.

Instead of using the rod 5 and film-guides 6, I can use the rod 5a which is fixed to the wall of the cover 2 I, in any suitable manner. Said rod 5a may be integral with the cover 2|. I can replace the film guides 6 by corresponding guides 55 which are adjustably fixed to the rod 5a, by means of clamping screws '56.

The guides 55 can be molded integrally with the cover 2|, either with or without the rod 5a, thus greatly lowering the cost of manufacture of the complete device. In such case, the guides 55 are not adjustable relative to each other.

The clamping frame is an optional feature.

Numerous changes and omissions and additions can be made in the foregoing, without departing from the scope of my invention.

In one aspect of my invention, it includes a tank which has a solution-holding compartment; means located in said compartment for taking up the film in spirally wound form, with the layers of the film separated from each other; a holder which is turnably associated with said tank, spaced from the developing-solution, said holder holding the film-spool on which the film and protective paper are spirally wound. Said tank has a cover, said cover and said tank having walls which define a channel through which the protective paper can be slid, in a direction reverse to the direction in which the film is unwound from its holding spool; said channel being shaped so that the protective paper can be forced through the same, solely by the force which is exerted on said protective paper by the unwinding of the film from the holding-spool.

This is per se a feature of my invention, irres ective of other elements of construction.

The adjacent walls of channel 43 are made of material which has a black or other dark color, so as to have minimum reflecting power. Said adiacent walls may be smooth. As an alternative, said adjacent walls may have rough surfaces, in order to reflect the light in all directions. Hence, even if there is no protective paper in channel 43. no light can enter through said channel to fall upon the film which is being developed, because the light which enters channel 43 is absorbed by its walls. For this purpose, the channel 43 is made of minimum depth, just enough to permit the paper P to slide through said channel.

The width of the paper P is preferably equal to the width of channel 43, but the paper may be of less width than said channel. The invention is not limited to the convex shape of the channel 43 which is disclosed as an illustration. It includes a channel 43 of any gradual contour, which excludes the light when the protective paper P is located therein. By a gradual contour, I define a contour which is sufficiently free from a sharp bend or bends, which would bend the protective paper P in said channel 43, so as to require a pulling force on said protective paper P, externally to the tank, in order to move the protective paper P through said channel. By eliminating such sharp bend or bends, I can move the protective paper P through said channel 43, solely by the pushing force which is exerted by the spool 30, when said spool is turned, in order to unwind the film and protective paper from said spool 30.

The invention is not limited to a tank device in which the walls of channel 43 are respective walls of the cover and of the tank. That is, in one aspect of the invention, the cover 2| can be considered as being part of the tank device, when the tank device is ready for operation, and while the film is being developed.

Fig. 11 shows the path of the paper P, in broken lines, from the take-up spool which is located within the holder l4, to the channel 43. In this embodiment, the paper P is led over the respective edge of the slit of holder 14, to the inner end of channel 43, in a curved path. In this embodiment, the optional deflector 53 is integral with cover 2|, although these parts may be nonintegral. The conclave bottom wall of deflector 53 is shaped so that its edge 53a, and a part of said concave bottom wall which directly precedes said edge 53a, is below the top of wall 40, thus providing additional protection against the entry of light. Said concave bottom wall of deflector '53 is also colored so that it has minimum reflecting power.

Fig. 12 shows an optional feature whereby each wall of channel 43 has a liner 43a fixed thereto. Each liner 43a is made of light-absorbent material. Said material can be soft and flexible and compressible. It may be made of any black pile fabric or filamentous fabric. The adjacent walls or filaments of said liners 43a normally contact with each other, in order to provide a seal against the entry of light. The protective paper P can slide easily between said liners 43a, with very little friction. The thickness of paper P may be about 0.004 inch, as an example. In this embodiment, if the width of the paper is less than the width of the channel 43, the remainder of the channel 43 is maintained light-tight by said liners 43a. However, said liners 43a are not a necessary part of the device.

Fig. 13 shows that the shoulder 44 of the holder I4, has a series of holes 44a; pins 44b, one of which is shown in Fig. 11, may be inserted into said holes 44a, with any desired spacing. A pair of such pins 44b therefore serves to guide the film across shoulder 44, to the guides 6, thus preventing the film from shifting laterally at shoulder 44. Each edge of the film either abuts one of said pins 441), or is very close to a respective pin 44b. The stop-shoulder 44 is an optional feature which may be omitted, although its use is preferred. If said shoulder 44 is omitted, I can use any other type of stop for holding the holder M in operative position.

I claim:

1..A light-tight tank device for developing photographic film, comprising a tank which has an open top, said tank having aligned walls, said walls being imperforate and having internal bearing recesses below said top, a spool-shaft mounted turnably in said bearing recesses, take-up spools fixed to said shaft, a pull-device, one end of said pull device being fixed to said shaft, a lighttight cover movably seated on the top of said tank, an operating shaft which is located above the top of said tank, said cover having coverbearings above the top of said tank in which said operating shaft is turnably mounted, means external to said cover for turning said operating shaft, means connecting said operating shaft and said spool-shaft.

2. A device for developing photographic film, comprising a tank which has an open top, a loader compartment fixed to an end-wall of said tank, said loader compartment being external to said tank and having an open top, a removable cover which is adapted to close said open top of said tank and said loader compartment, said loader compartment having a top wall which is spaced from the respective part of the bottom face of said cover when said cover is in position to close said tank, said top wall and said respective part of said bottom face of said cover being shaped to form a longitudinal exit channel for said loader compartment when said cover is in said tank-closing position, said cover closing said open top of said loader compartment save at said exit channel when said cover is in said tank-closing position, a loader which is turnably supported in said loader compartment to turn around a transverse axis, said loader having a transverse slit, said holder being shaped to receive a roll of film and protective paper, longitudinal pull means located and adapted to grip said film and to pull it longitudinally into said tank in a direction away from said exit channel and through said slit so as to simultaneously unwind said film and said protective paper off said roll, said longitudinal pull means turning said loader around said transverse axis into an unwinding position, said loader having a stop which abuts the wall of said loader compartment when said loader is in said unwinding position, said slit having a transverse paper-guiding edge which is located to guide said protective paper when said paper is thus unwound from said roll and said loader is in said unwinding position, said paper-guiding edge being located substantially directly vertically below the inner end of said exit channel when said loader is in said unwinding position, said exit channel extending downwardly from its inner end to its outer end, said outer end being longitudinally further away from said tank than said inner end, said exit channel being free from sharp bends so that the paper is automatically fed through said exit channel when said roll is thus unwound.

SAMUEL FREEMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,352,109 Beidler Sept. '7, 1920 1,542,530 Salins June 16, 1925 2,082,962 Lesjak et a] June 8, 1937 2,112,605 Pless Mar. 29, 1938 2,214,581 Freeman Sept. 10, 1940 2,367,424 Nichols i Jan. 16, 1945 FOREIGN PATENTS Number Country Date 641,858 Germany Jan. 16, 1936 491,231 Great Britain Jan. 8, 1938 696,298 Germany Apr. 14, 1939 209,869 Switzerland Aug. 1, 1940 

